Water is drawn from the Vaal to meet the industrial needs of the Greater Johannesburg Metropolitan Area and a large part of the Free State. As a part of the Vaal-Hartz Scheme it is a major source of water for irrigation. Water drawn from the Vaal supports 12 million consumers in Gauteng and surrounding areas.[5]

Vaal is a Dutch name (later Afrikaans), translated by the Griquas or Boers[7] from an earlier Kora Khoikhoi name Tky-Gariep (/hei !garib, drab river).[8] Both Vaal and Tky mean "drab" or "dull", which alludes to the colour of the waters, especially noticeable during flood season when the river carries a lot of silt. In the upper reaches the river was named Likwa (Sindebele), Ikwa (isiZulu), ilikwa (siSwati), lekwa (Sesotho), or cuoa by the Khoikhoi, all referring to the plain it traverses.[8]